On Jul 24, 2015, at 12:30 PM, Ken Dibble <[email protected]> wrote:
>> Somewhere hiding in the registry, some GUID is incorrectly associated with >> the VFP install. How that can happen is a mystery that only a Microsoft >> engineer can explain. > > Well I have an explanation--but I'm sure everyone here will laugh. Only if they ever studied probability. ;-) > GUID-generation is based on the notion that it is "highly unlikely" or > "extremely improbable" that two generation processes will get the same > result. But it is NOT mathematically impossible. > > Yes, it's highly unlikely that if you flip a coin 10 times the first 9 times > you will get "heads". But it happens nonetheless, sometimes. The probability of heads 9 times in a row == 2**9 == 1 in 512 The probability of generating two identical UUIDs is more complex, so I'll leave you with a link: https://en.wikipedia.org/wiki/Universally_unique_identifier#Random%5FUUID%5Fprobability%5Fof%5Fduplicates Summary: "To put these numbers into perspective, the annual risk of a given person being hit by a meteorite is estimated to be one chance in 17 billion,[4] which means the probability is about 0.00000000006 (6 × 10−11), equivalent to the odds of creating a few tens of trillions of UUIDs in a year and having one duplicate. In other words, only after generating 1 billion UUIDs every second for the next 100 years, the probability of creating just one duplicate would be about 50%." -- Ed Leafe --- StripMime Report -- processed MIME parts --- multipart/signed text/plain (text body -- kept) application/pgp-signature --- _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/[email protected] ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
